Since cotton may vary in quality from bale to bale, it is conventional procedure for mills to blend fibers from a number of different bales in order to obtain a substantially uniform supply of fibers from which to produce yarns.
One common procedure utilized in textile mills for blending of fibers involves laying down a plurality of fiber bales behind each of a series of blending feeder machines and manually pulling portions from the bales and depositing the portions into the respective hoppers of the blending feeders. The delivery ends of the series of blending feeders are interconnected to combine the fibrous output and provide a blend of fibers from all of the bales on the floor. As many as ten to twelve blending feeder machines may be employed in a single bale opening line with from six to eight or more bales being arranged behind each blending feeder.
It will be readily appreciated that this type of fiber blending arrangement requires a considerable amount of floor space in the opening room of a mill and necessitates constant attention from an operator in order to keep the hoppers of the blending feeders filled with fibers. Additionally, the blending feeders are relatively expensive machines and require frequent maintenance and adjustment for proper operation.
Further, even though fibers are taken from a large number of bales, variations in the blend of fibers achieved may still occur because of the manner in which the bales are opened. In this regard, it will be understood that relatively large chunks or layers of fibers are removed from the respective bales and are deposited into the hoppers of the blending feeders. Since the quality of the fibers may vary from layer to layer within a bale due to the way in which the bales are produced in a bale press, as well as varying in quality from bale to bale, removal of an entire fiber layer at a time in the manner described may result in undesirable non-uniformity or variations in the blend of fibers obtained. Also, when blending is performed manually there is a likelihood that the person responsible for keeping the hoppers filled with fibers will not remove fibers from each and every bale on the floor, and this further contributes to non-uniformity in the blend of fibers.
To eliminate the laborious task of manually removing fibers from the bales, various types of automated bale opening machines have been developed. A principle of operation utilized in many commercially available bale opening devices involves moving the fiber bales over a rotating spiked opener roller or belt and removing fibers from the underside of the respective bales. However, it has been determined that removing fibers in this manner results in breaking or rupturing a significant number of the fibers as well as causing undesirable entanglements or neps which may show up as defects in the yarn or fabric produced from the fiber. Further, this type of bale opening device is not well suited to blending fibers from a number of fiber bales. Those devices, such as the "carrousel type" bale opener which do provide for blending from a number of different bales generally require an undesirably large amount of floor space.
A principle of operation utilized in other types of proposed or commercially available bale opening devices, as shown in several recent patents, involves moving a fiber removing device longitudinally above and along a row of fiber bales to remove fibers from the upper surfaces of the bales. For example, in Alt et al. U.S. Pat. No. 3,736,624, a rotating fiber opening roller is reciprocated across the tops of a series of stationary bales to remove layers of fibers therefrom. Other devices, such as those shown in Goldammer U.S. Pat. No. 3,443,285, Van Doorn U.S. Pat. No. 3,531,831, and in Keller U.S. Pat. Nos. 3,777,908, 3,951,282 and 3,986,623 employ grippers which are movable relative to the bales and which grasp and remove masses of fibers from the respective bales. In the devices shown in the Goldammer and Keller patents, the grippers take relatively large masses of fibers from a bale with each grasp. These devices remove fibers from the bales layer by layer in a manner similar in many respects to the previously noted manual technique for opening fiber bales, and thus suffer many of the same disadvantages with respect to obtaining a desirable blend of fibers from the bales. These devices also require the use of a series of relatively expensive blending feeder machines, as in the above-described manual technique, and thus also require a large amount of floor space in the opening room.
The Van Doorn patent discloses a plucker unit which moves along a series of fiber bales and removes smaller masses of fibers from the bales, employs a series of chains carrying plucking members for removing the fibers, as well as a complicated assembly of numerous other moving parts, all of which are subject to wear and to fouling by the fibers and lint produced incident to the plucking operation. The Van Doorn device requires a massive and complicated system for supporting the plucker unit above the series of bales and for gradually lowering the same as the bales are reduced in height, with the device being thus limited to batchwise operation on a plurality of bales. In order to operate in a substantially continuous manner, it is necessary to provide extra bins alongside the plucker unit for holding extra rows of bales. Further, the construction and arrangement of the plucking members of the Van Doorn device has a tendency to undesirably compact the fibers of the bales as the plucking members are moved downwardly into engagement with the bales during operation of the device.
With the foregoing in mind it is an important object of the present invention to provide a method and apparatus for removing and blending fibers from fiber bales which overcomes the disadvantages and limitations of the prior manual and automated bale opening practices.
It is another important object of this invention to provide a method and apparatus for removing and blending fibers from a plurality of fiber bales and wherein a highly uniform blend of fibers from the respective bales is obtained.
It is another object of the present invention to provide a method and apparatus for opening fiber bales which accounts for variations in fiber properties from bale to bale and also within each bale so as to thereby provide a highly uniform blend of fibers from the respective bales.
It is a further object of the invention to provide a method and apparatus of the type described in which the fibers removed from the bales are so well blended that some of the subsequent processing steps normally required for further blending may be eliminated if desired.
It is a further object of the invention to provide a method and apparatus of the type described wherein the uniform blend of fibers is accomplished with less equipment and with more simplified apparatus than in the prior bale opening devices.
It is still another object of the present invention to provide a method and apparatus of the type described wherein the fibers removed from the bales are in a much more opened state to thus eliminate the need for significant additional opening of the fibers prior to further processing.